This week's meetings are the first face-to-face discussions since early-December, when Mr Trump and Chinese President Xi Jinping agreed to a 90-day truce — during which no new tariffs would be imposed on each other's imports.

If no deal is reached by March 2, Mr Trump has said he will proceed with raising tariffs.

They would increase to 25 per cent (up from its current 10 per cent) on $US200 billion worth of Chinese imports at a time when China's economy is slowing significantly.

"You're seeing some negotiations happen and the market is starting to think that perhaps we'll start to see a framework evolve," said Anik Sen, global head of equities at PineBridge Investments.

Cautiously optimistic boost

The benchmark S&P 500 rose 1 per cent to 2,574, and the tech-heavy Nasdaq lifted 1.1 per cent to 6,897.

Consumer discretionary stocks, particularly Amazon, provided the largest boost to US markets.

Amazon's share price jumped 1.7 per cent to $US1,656.58, taking its total market value up to $US809 billion.

The online retailer is now America's most valuable company, eclipsing Apple ($US715b) and Microsoft ($US788b).

Apple's stock lifted 1.9 per cent to $US150.75, recovering slightly from last week's sell-off — after the company warned of disappointing sales due to the weakening Chinese economy and rising US-China tensions.

But there was a significant drop in chip-maker stocks, with Nvidia and Applied Materials down 2.5 and 4.1 per cent respectively.

The fall was sparked byKorean tech giant Samsung's warning that its fourth-quarter profit would be sharply lower than expected — due to weaker demand for memory chips and intensifying competition in the smartphone segment.

Samsung downgraded its earnings forecast, stating that its December-quarter profit would be around $13.5 billion (10.8 trillion Korean won), down 28.7 per cent compared to last year.

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